JP6898494B2 - Drive mechanism and seatbelt retractor - Google Patents

Description

The present invention relates to a drive mechanism capable of changing the magnitude of output (rotational torque) to an operating shaft, which is a driven member, by switching the rotation direction of the electric actuator, and a seatbelt retractor to which the drive mechanism is applied.

Conventionally, a seatbelt retractor provided in a seatbelt device winds and pulls out the seatbelt by rotating the spindle, and locks the rotation of the spindle by a locking mechanism in an emergency such as a vehicle collision to lock the seatbelt. Block the withdrawal of.

Further, as such a retractor for a seatbelt, when a sudden deceleration state of the vehicle is detected by a sensor, the spindle is rotated in the winding direction by an electric actuator, the seatbelt is wound by a certain amount, and the occupant is lightly restrained. , It is known that when a collision is detected, an explosive type pretensioner is operated to strongly wind up the seat belt to securely restrain the occupant (see, for example, Patent Document 1). Here, the former function of lightly winding the seatbelt when a sudden deceleration state is detected is called a "pre-pretension (PP) function", and the latter function of strongly winding the seatbelt when a collision is detected is called "pretension (PT)". It is called "function".

That is, in the seatbelt retractor described in Patent Document 1, the pretensioner, which is a means for performing the pretension (PT) function, is configured by using a gas generator that generates high-pressure gas in an emergency as a drive source. Further, the pre-pretensioner, which is a means for performing the pre-pretension (PP) function, is configured by using an electric actuator as a drive source.

Japanese Unexamined Patent Publication No. 2011-162157

As described above, in the conventional seatbelt retractor, the pretensioner and the pre-pretensioner are configured by using separate drive sources. Therefore, there is a problem that the number of parts increases, it is difficult to reduce the size and weight, and the cost tends to be high.

The present invention has been made in view of the above circumstances, and an object of the present invention is to change the size of the output transmitted to the operating shaft while reducing the size, weight, and cost by reducing the number of parts. It is an object of the present invention to provide a drive mechanism and a seatbelt retractor in which the structure of the pretensioner and the pre-pretensioner is simplified by applying the drive mechanism.

The above object of the present invention is achieved by the following configuration.
(1) An operating shaft that can rotate in the A and B directions when one direction of the rotation direction is the A direction and the other direction is the B direction.
An electric actuator that generates rotational output in the forward and reverse directions to rotate the operating shaft, and
A power transmission mechanism that transmits power between the electric actuator and the operating shaft,
With
The power transmission mechanism
A first gear mechanism that has a first final gear that can rotate integrally with the operating shaft and can transmit power from the electric actuator.
A second gear mechanism that has a second final gear that can rotate integrally with the operating shaft and can transmit power from the electric actuator.
A control gear arranged between the electric actuator and the first gear mechanism and the second gear mechanism to transmit the rotation of the electric actuator to the first gear mechanism and the second gear mechanism.
Intervened between the first gear mechanism and the control gear, when the electric actuator rotates in the forward direction, the connection between the first gear mechanism and the control gear is turned on, and the electric actuator moves in the opposite direction. When rotating, the first clutch that turns off the connection between the first gear mechanism and the control gear, and
Intervened between the second gear mechanism and the control gear, when the electric actuator rotates in the opposite direction, the connection between the second gear mechanism and the control gear is turned on, and the electric actuator moves in the forward direction. It has a second clutch that turns off the connection between the second gear mechanism and the control gear when rotating.
A drive mechanism characterized in that the gear ratio of the first gear mechanism and the gear ratio of the second gear mechanism are set to different values.
(2) The first clutch can be coupled to the first latch gear that rotates integrally with the first first stage gear of the first gear mechanism and the outer peripheral teeth of the first latch gear, and rotates integrally with the control gear. With a possible first coupling member,
The second clutch can be coupled to a second latch gear that rotates integrally with the second first stage gear of the second gear mechanism and outer peripheral teeth of the second latch gear, and can rotate integrally with the control gear. With 2 coupling members
The first first stage gear and the second first stage gear are provided coaxially with the control gear.
The drive mechanism according to (1), wherein the first coupling member and the second coupling member are connected to each other.
(3) The first clutch can be coupled to the first clutch housing that rotates integrally with the first first stage gear of the first gear mechanism and the inner peripheral teeth of the first clutch housing, and is integrated with the control gear. With a first coupling member that is rotatable
The second clutch can be coupled to the second clutch housing that rotates integrally with the second first stage gear of the second gear mechanism and the inner peripheral teeth of the second clutch housing, and rotates integrally with the control gear. With a possible second coupling member,
The first first stage gear and the second first stage gear are provided coaxially with the control gear.
The drive mechanism according to (1), wherein the first coupling member and the second coupling member are connected to each other.
(4) Either one of the first gear mechanism or the second gear mechanism sets the rotation direction of the output shaft of the electric actuator between the electric actuator and the first final gear or the second final gear. The drive mechanism according to any one of (1) to (3), comprising an idle gear that reverses the direction.
(5) The first clutch and the second clutch are clutches having the same characteristics, and when the electric actuator is OFF, both the first clutch and the second clutch have the gear mechanism and the control gear. The drive mechanism according to any one of (1) to (4), which can be held in a state where the connection is turned off.
(6) A first rotation angle sensor disposed between the first and second clutches and the electric actuator to detect a rotation angle, and
A second rotation angle sensor, which is arranged between the first clutch and the operating shaft or between the second clutch and the operating shaft and detects a rotation angle, is provided.
When the relative angle difference between the first rotation angle sensor and the second rotation angle sensor reaches a predetermined value, the disengagement rotation of the first clutch and the second clutch by the electric actuator is stopped. The drive mechanism according to any one of (1) to (5).
(7) The drive according to (6), wherein the second rotation angle sensor is arranged in the gear mechanism on the side where the gear ratio is larger among the first gear mechanism and the second gear mechanism. mechanism.
(8) The rotation angle of the first gear mechanism or the second gear mechanism not provided with the second rotation angle sensor is the detection angle of the second rotation angle sensor, the gear ratio of the first gear mechanism, and the first. 2. The drive mechanism according to (7), wherein the drive mechanism is obtained by calculation from the ratio of the gear mechanism to the gear ratio.
(9) When the winding direction of the seat belt is the A direction and the pulling direction of the seat belt is the B direction, the spindle that can rotate in the A direction and the B direction, and
An electric actuator that generates rotational output in the forward and reverse directions to rotate the spindle, and
A power transmission mechanism that transmits power between the electric actuator and the spindle,
With
The power transmission mechanism
A first gear mechanism that has a first final gear that can rotate integrally with the spindle and can transmit power from the electric actuator.
A second gear mechanism that has a second final gear that can rotate integrally with the spindle and can transmit power from the electric actuator.
A control gear arranged between the electric actuator and the first gear mechanism and the second gear mechanism to transmit the rotation of the electric actuator to the first gear mechanism and the second gear mechanism.
Intervened between the first gear mechanism and the control gear, when the electric actuator rotates in the forward direction, the connection between the first gear mechanism and the control gear is turned on, and the electric actuator moves in the opposite direction. When rotating, the first clutch that turns off the connection between the first gear mechanism and the control gear, and
Intervened between the second gear mechanism and the control gear, when the electric actuator rotates in the opposite direction, the connection between the second gear mechanism and the control gear is turned on, and the electric actuator moves in the forward direction. It has a second clutch that turns off the connection between the second gear mechanism and the control gear when rotating.
A seatbelt retractor characterized in that the gear ratio of the first gear mechanism and the gear ratio of the second gear mechanism are set to different values.
(10) The first clutch can be coupled to the first latch gear that rotates integrally with the first first stage gear of the first gear mechanism and the outer peripheral teeth of the first latch gear, and rotates integrally with the control gear. With a possible first coupling member,
The second clutch can be coupled to a second latch gear that rotates integrally with the second first stage gear of the second gear mechanism and outer peripheral teeth of the second latch gear, and can rotate integrally with the control gear. With 2 coupling members
The first first stage gear and the second first stage gear are provided coaxially with the control gear.
The seatbelt retractor according to (9), wherein the first coupling member and the second coupling member are connected to each other.
(11) The first clutch can be coupled to the first clutch housing that rotates integrally with the first first stage gear of the first gear mechanism and the inner peripheral teeth of the first clutch housing, and is integrated with the control gear. With a first coupling member that is rotatable
The second clutch can be coupled to the second clutch housing that rotates integrally with the second first stage gear of the second gear mechanism and the inner peripheral teeth of the second clutch housing, and rotates integrally with the control gear. With a possible second coupling member,
The first first stage gear and the second first stage gear are provided coaxially with the control gear.
The seatbelt retractor according to (9), wherein the first coupling member and the second coupling member are connected to each other.
(12) Either one of the first gear mechanism or the second gear mechanism causes the rotation direction of the output shaft of the electric actuator between the electric actuator and the first final gear or the second final gear. The seatbelt retractor according to any one of (9) to (11), which includes an idle gear that reverses the direction.
(13) The first clutch and the second clutch are clutches having the same characteristics, and when the electric actuator is OFF, both the first clutch and the second clutch are connected to the final gear and the spindle. The seatbelt retractor according to any one of (9) to (12), wherein the retractor can be held in a state of being turned off.
(14) A first rotation angle sensor disposed between the first and second clutches and the electric actuator to detect a rotation angle, and
A second rotation angle sensor, which is arranged between the first clutch and the spindle or between the second clutch and the spindle to detect a rotation angle, is provided.
When the relative angle difference between the first rotation angle sensor and the second rotation angle sensor reaches a predetermined value, the disengagement rotation of the first clutch and the second clutch by the electric actuator is stopped. The seatbelt retractor according to any one of (9) to (13).
(15) The seat according to (14), wherein the second rotation angle sensor is arranged in the gear mechanism on the side where the gear ratio is larger among the first gear mechanism and the second gear mechanism. Retractor for belt.
(16) The rotation angle of the first gear mechanism or the second gear mechanism not provided with the second rotation angle sensor is the detection angle of the second rotation angle sensor, the gear ratio of the first gear mechanism, and the first. The retractor for a seat belt according to (15), wherein the retractor for a seat belt is obtained by calculation from the ratio of the two-gear mechanism to the gear ratio.

According to the drive mechanism and the seatbelt retractor of the present invention, the magnitude of the output transmitted to the operating shaft and the spindle can be changed by switching the rotation direction of the electric actuator. For example, depending on how the gear ratio is set, when the electric actuator is rotated in the forward direction, a small torque is transmitted to the operating shaft and spindle, and when the electric actuator is rotated in the opposite direction, it is transmitted to the operating shaft and spindle. Can transmit a large torque. Therefore, the number of parts can be reduced by simplifying the configuration, which makes it possible to reduce the size and weight and realize the cost reduction. Therefore, by applying it to a seatbelt retractor, it is possible to fulfill both the pre-pretension (PP) function and the pre-tension (PT) function by switching the rotation direction of one electric actuator.

It is a schematic side view of the retractor for a seat belt which concerns on 1st Embodiment of this invention. It is a perspective view which shows the principle structure of the power transmission mechanism of the retractor. It is explanatory drawing of the rotation direction of each element of a power transmission mechanism when a motor rotates forward. It is explanatory drawing of the rotation direction of each element of a power transmission mechanism when a motor rotates in the reverse direction. It is explanatory drawing of the clutch, and is the front view which shows the state of the clutch OFF when the final gear is not rotating. In the explanatory view of the clutch, the front view shows that when the final gear rotates in the A direction (winding direction), the clutch is turned on and the clutch housing connected to the spindle rotates in the A direction (winding direction). is there. In the explanatory view of the clutch, it is a front view which shows the state at the initial time when the final gear rotates in the B direction (the release direction), and the transition from the clutch ON to the clutch OFF begins. In the explanatory view of the clutch, it is a front view which shows the state which the clutch is completely turned off by further rotating the final gear in the B direction (the release direction). It is a characteristic diagram for demonstrating how the ON / OFF state of two clutches is switched according to the rotation of a motor. It is a schematic side view of the retractor for a seat belt of the 2nd Embodiment of this invention. It is a schematic side view of the retractor for a seat belt of the 3rd Embodiment of this invention. It is a perspective view which shows a part of the power transmission mechanism of FIG. It is a perspective view which shows a part of the power transmission mechanism in which both the 1st and 2nd clutches are in the OFF state, excluding the control gear. (A) is an explanatory diagram of the power transmission path due to the rotation of the spindle when both the first and second clutches are in the OFF state while the motor is stopped, and (b) is the power transmission path when the motor rotates in the forward and reverse directions. It is explanatory drawing of. The first and second clutch operation explanatory views, (a) to (c) are front views showing a state in which the connection of the first clutch is turned on when the control gear rotates in the A direction, (d) to (d). f) is a front view showing a state in which the connection of the second clutch is turned ON when the control gear rotates in the B direction. It is a graph which shows the relationship between the detection angle of the control gear and the first stage gear by the 1st and 2nd rotation angle sensors, the relative rotation angle of both, and time. It is a schematic side view of the retractor for a seat belt of the 4th Embodiment of this invention. (A) is a perspective view of a control gear incorporating the first and second clutches, and (b) is a perspective view of the first and second coupling members. (A) is a front view of the first clutch in the OFF state, (b) is a front view of the second clutch in the OFF state, and (c) is a front view of the first clutch that is turned on by the counterclockwise rotation of the control gear. , (D) is a front view of the second clutch that is completely turned off by the counterclockwise rotation of the control gear, and (e) is a front view of the first clutch that is completely turned off by the clockwise rotation of the control gear. (F) is a front view of the second clutch which is turned on by the clockwise rotation of the control gear.

Next, the seatbelt retractor according to each embodiment of the present invention will be described in detail with reference to the drawings.

(First Embodiment)
As shown in FIGS. 1 and 2, the seatbelt retractor 10 of the present embodiment includes a spindle 12 for winding the seatbelt 1 and a take-up spring device 13 for urging the spindle 12 in the winding direction of the seatbelt 1. A lock mechanism 14 that locks the pull-out operation of the seatbelt 1 according to an acceleration detected by an acceleration sensor (not shown), a motor 15 as an electric actuator that generates power to rotate the spindle 12, and a motor 15 and a spindle. It has a power transmission mechanism 20 capable of transmitting power to and from 12. Here, the motor 15 and the power transmission mechanism 20 also serve as a pretensioner and a pre-pretensioner, and a conventional explosive type pretensioner is not provided.

Both ends of the spindle 12 are rotatably supported by the retractor frame 11A. A torsion bar (not shown) constituting an energy absorption mechanism is provided in the spindle 12. A power transmission mechanism 20 is arranged on one end side of the retractor frame 11A. The power transmission mechanism 20 is housed inside the gear cover 11B coupled to the retractor frame 11A. A take-up spring device 13 is attached to the outside of the gear cover 11B.

Here, in FIGS. 1 and 2, assuming that the rotation direction of the spindle 12 that rotates the retractor 10 counterclockwise when viewed from the left is the A direction and the rotation direction of the spindle 12 that rotates clockwise is the B direction. The spindle 12 is rotatable in the A direction and the B direction. That is, the spindle 12 of the present embodiment winds up the seatbelt 1 by rotating in the A direction, and pulls out the seatbelt 1 by rotating in the B direction.
Further, as shown in FIGS. 3 and 4, the motor 15 can rotate in the forward and reverse directions, and the rotation in the forward direction (forward rotation) is represented by the arrow symbol N1 and the rotation in the reverse direction (reverse rotation) is represented by the arrow symbol N2. .. Note that forward rotation and reverse rotation merely define rotation in one direction and rotation in the other direction for convenience.

The power transmission mechanism 20 includes a first gear mechanism 21, a second gear mechanism 22, a first clutch 41, and a second clutch 42. The first gear mechanism 21 is composed of a gear train from the input gear 30 attached to the output shaft 15a of the motor 15 to the first final gear 31. The second gear mechanism 22 is composed of a gear train from the input gear 30 attached to the output shaft 15a of the motor 15 to the second final gear 32.

The first final gear 31 of the first gear mechanism 21 and the second final gear 32 of the second gear mechanism 22 rotate in opposite directions when the motor 15 rotates, so that the gear train of the first gear mechanism 21 and the second final gear 32 rotate in opposite directions. A gear train of the gear mechanism 22 is configured (this configuration is referred to as "condition 1"). Further, the gear ratio (reduction ratio) of the first gear mechanism 21 is set to be about 10 times larger than the gear ratio of the second gear mechanism 22 (this configuration is referred to as "condition 2").

The gear ratio = (number of output gear teeth) / (number of input gear teeth). For example, assuming that the gear ratio of the first gear mechanism 21 is 10 times larger than the gear ratio of the second gear mechanism 22, the first final gear 31 of the first gear mechanism 21 has a second gear mechanism for the same motor rotation speed. The torque of 10 times is output at 1/10 of the rotation speed of the 2nd final gear 32 of 22.

In the example shown in FIGS. 2 to 4, the first gear mechanism 21 is composed of a combination of an input gear 30 attached to the output shaft 15a of the motor 15 and a first final gear 31 that meshes with the input gear 30. ing. Further, the second gear mechanism 22 is a combination of an input gear 30 attached to the output shaft 15a of the motor 15, an idle gear 33 that meshes with the input gear 30, and a second final gear 32 that meshes with the idle gear 33. It is configured. By providing the idle gear 33 in the gear train of the second gear mechanism 22, the first final gear 31 of the first gear mechanism 21 and the second final gear 32 of the second gear mechanism 22 rotate in opposite directions.

The configuration of the gear train of the first gear mechanism 21 and the gear train of the second gear mechanism 22 may be any as long as it satisfies the above conditions 1 and 2, depending on the layout relationship and the gear ratio relationship. Therefore, more complicated gear combinations may be adopted.

By adopting a configuration that satisfies such condition 1, as shown in FIGS. 3 and 4, in the first gear mechanism 21, when the motor 15 rotates in the forward direction (forward rotation N1), the motor 15 from the motor 15. When the first final gear 31 rotates in the A direction due to the transmission of power and the motor 15 rotates in the opposite direction (reverse rotation N2), the first final gear 31 rotates in the B direction due to the transmission of power from the motor 15. .. Further, in the second gear mechanism 22, when the motor 15 rotates in the forward direction (forward rotation N1), the second final gear 32 rotates in the B direction due to the transmission of power from the motor 15, and the motor 15 rotates in the opposite direction. When rotating (reverse rotation N2), the second final gear 32 rotates in the A direction due to the transmission of power from the motor 15.

Further, as shown in FIG. 3, the transmission is transmitted by the first gear mechanism 21 because the condition 2 is satisfied, that is, the gear ratio of the first gear mechanism 21 is set to be larger than the gear ratio of the second gear mechanism 22. When the spindle 12 is rotated in the A direction by the driving force, the spindle 12 is rotated with a large torque. As a result, the seat belt 1 can be wound while applying a large tension T1. Further, as shown in FIG. 4, when the spindle 12 is rotated by the driving force transmitted by the second gear mechanism 22, the spindle 12 is rotated with a small torque. As a result, the seat belt 1 can be wound while applying a small tension T2.

That is, by setting the gear ratio of the first gear mechanism 21> the gear ratio of the second gear mechanism 22, the relationship of the output torque T1 by the first gear mechanism 21> the output torque T2 by the second gear mechanism 22 is established.

Therefore, in the retractor 10, the output torque T1 by the first gear mechanism 21 is used as a pretensioner (PT), and the output torque T2 by the second gear mechanism 22 is used as a pre-pretensioner (PP).

Next, the clutches 41 and 42 will be described.
The first final gear 31 of the first gear mechanism 21 and the second final gear 32 of the second gear mechanism 22 are connected to the spindle 12 via the first clutch 41 and the second clutch 42, respectively. In each of the clutches 41 and 42, when the final gears 31 and 32 rotate in the A direction, the connection between the final gears 31 and 32 and the spindle 12 is turned ON (clutch ON), and the final gears 31 and 32 rotate in the B direction. At that time, the connection between the final gears 31 and 32 and the spindle 12 is turned off (clutch is turned off).

Specifically, when the first clutch 41 interposed between the first final gear 31 of the first gear mechanism 21 and the spindle 12 rotates relative to the spindle 12 in the A direction, the first clutch 41 , When the connection between the first final gear 31 and the spindle 12 is turned on (state in FIG. 3) and the first final gear 31 rotates relative to the spindle 12 in the B direction, the first final gear 31 and the spindle 12 The connection is turned off (state in FIG. 4). Further, the second clutch 42 interposed between the second final gear 32 of the second gear mechanism 22 and the spindle 12 is second when the second final gear 32 rotates relative to the spindle 12 in the A direction. When the connection between the final gear 32 and the spindle 12 is turned on (state in FIG. 4) and the second final gear 32 rotates relative to the spindle 12 in the B direction, the connection between the second final gear 32 and the spindle 12 is made. Turn off (state in FIG. 3). The clutches 41 and 42 are connected not only when the spindle 12 is stopped but also when the clutches 41 and 42 are rotated by the urging force of the take-up spring device 13.

The first clutch 41 and the second clutch 42 are clutches having the same characteristics, and when the motor 15 is OFF, that is, when the final gears 31 and 32 are not rotating, the final gears 31 and 32 and the spindle are both used. It is possible to hold the connection with 12 in a state of being turned off.

Any type of clutches 41 and 42 can be adopted, and an example is given in FIGS. 5 to 8. The configurations and operations of the clutches 41 and 42 will be described with reference to FIGS. 5 to 8. In principle, the clutches 41 and 42 switch between clutch ON and clutch OFF by two pouls 50 and a friction ring 60, similarly to those shown in Patent Document 1.

As shown in FIGS. 5 to 8, the clutches 41 and 42 are provided in the inner cylindrical wall 35 integrally provided on the final gears 31 and 32 and in the powl sliding groove 36 formed in the inner cylindrical wall 35, respectively. Two slidably housed powls 50, a friction ring 60 arranged on the inner peripheral side of the inner cylindrical wall 35, and an outer cylindrical wall of the clutch housing 43 arranged on the outer peripheral side of the inner cylindrical wall 35. It is configured to include a fixing ring 5 provided on a fixing side member such as a retractor frame 11A or a gear cover 11B so as to be located on the inner peripheral side of the friction ring 60. The final gears 31 and 32 are rotationally driven by the motor 15 in the A direction (winding direction) or the B direction (pulling direction = releasing direction).

The clutch housing 43 is coupled to the spindle 12 so as to rotate integrally, and has internal teeth 43a to which the powl 50 engages on the inner peripheral surface of the outer cylindrical wall. A spring core (not shown) of the take-up spring device 13 is connected to the clutch housing 43, and the take-up spring device 13 always urges the spindle 12 and the clutch housing 43 in the take-up direction (A direction). doing.

The outer peripheral surfaces of the inner cylindrical walls 35 of the final gears 31 and 32 face the internal teeth 43a of the clutch housing 43 so as to be relatively rotatable. A pair of Paul sliding grooves 36 for holding the pair of Pauls 50 are formed on the inner cylindrical walls 35 of the final gears 31 and 32. The pair of Paul sliding grooves 36 are arranged at positions facing each other by 180 ° in the circumferential direction. One end of the powl 50 is housed in the powl sliding groove 36, and the engaging claw 51 on the other end side extends to the outside of the powl sliding groove 36. Each of the pawls 50 is arranged so that the engaging claw 51 faces the internal teeth 43a of the clutch housing 43. The poul 50 is displaceable between a radial outer position where the engaging claw 51 engages the internal tooth 43a and a radial inner position where the engaging claw 51 does not engage the internal tooth 43a. ..

The friction ring 60 includes an annular portion 61, a pair of protrusions 62 projecting at opposite pole positions (positions facing 180 °) on the outer circumference of the annular portion 61, and a plurality of protrusions extending on the inner circumference of the annular portion 61. The contact piece 63 and the contact piece 63 are provided. Each contact piece 63 is in pressure contact with the outer peripheral surface of the fixing ring 5. Therefore, when the contact piece 63 receives a force in the rotational direction, it generates a frictional force in the direction opposite to the rotational direction with the fixing ring 5. A pair of protrusions 62 provided on the outer peripheral side of the friction ring 60 are inserted into the engaging grooves 52 of each poul 50.

Next, the operations of the clutches 41 and 42 will be described with reference to FIGS. 5 to 8.
First, as shown in FIG. 5, when the final gears 31 and 32 are not rotating, the paw 50 is located at the innermost part of the powl sliding groove 36. In this case, the engaging claw 51 of the paw 50 is located inward from the internal teeth 43a of the clutch housing 43, the clutch housing 43 and the powl 50 are not engaged, and the clutch is in the disengaged state. Therefore, only the clutch housing 43 integrated with the spindle 12 can rotate without being affected by the motor 15 and the gear mechanisms 21 and 22, and the seat belt 1 can be normally wound and pulled out.

Next, as shown in FIG. 6, when the final gears 31 and 32 rotate in the A direction (winding direction), the inner cylindrical wall 35 holding the paw 50 rotates in the A direction, and a pair of protrusions of the friction ring 60. Each poul 50 is displaced in the A direction with respect to the portion 62. When the inner wall of the engagement groove 52 of the paw 50 in the B direction (opposite direction to the A direction) hits the protrusion 62, the poul 50 pushes the friction ring 60 in the A direction, but the contact piece 63 of the friction ring 60 is fixed. Since it is in pressure contact with the outer periphery of the ring 5, the friction ring 60 tries to stay in place due to the frictional urging force between the contact piece 63 and the fixing ring 5. Therefore, as the final gears 31 and 32 rotate in the A direction, the paw 50 slides relatively in the paw sliding groove 36 in the B direction and is guided by the powl sliding groove 36 to guide the paw 50. The engaging claw 51 is displaced outward in the radial direction.

When the final gears 31 and 32 rotate in the A direction to a predetermined angle (here, 35.7 ° ± 2.2 °), the engaging claw 51 of the paw 50 engages with the internal teeth 43a of the clutch housing 43. The clutch is completely on. Therefore, when this state is established, the clutch housing 43 (spindle 12) receives the rotation of the final gears 31 and 32 and rotates in the A direction (winding direction). At that time, the friction ring 60 maintains the clutch ON state by sliding and rotating with the outer circumference of the fixing ring 5 while receiving a frictional urging force.

Next, when the final gears 31 and 32 rotate in the B direction (pull-out direction) from the state where the clutch is ON, as shown in FIG. 7, the inner cylindrical wall 35 holding the paw 50 rotates in the B direction, and the friction ring Each poul 50 is displaced in the B direction with respect to the pair of protrusions 62 of 60. Then, when the final gears 31 and 32 further rotate in the B direction and the inner wall of the engagement groove 52 of the paw 50 in the A direction hits the protrusion 62 of the friction ring 60, the poul 50 moves the friction ring 60 in the B direction. However, since the contact piece 63 of the friction ring 60 is in pressure contact with the outer periphery of the fixing ring 5, the friction ring 60 is in place due to the frictional urging force between the contact piece 63 and the fixing ring 5. Try to stay in. Therefore, as the final gears 31 and 32 rotate in the B direction, the paw 50 slides relatively in the paw sliding groove 36 in the A direction and is guided by the powl sliding groove 36 to guide the paw 50. The engaging claw 51 begins to displace inward in the radial direction. The rotation angles of the final gears 31 and 32 in the B direction at this stage are, for example, 10 ° ± 2.2 °.

Then, as shown in FIG. 8, when the final gears 31 and 32 rotate in the B direction to a predetermined angle (here, 25 ° ± 2.2 °), the engaging claw 51 of the pole 50 is inside the clutch housing 43. Apart from the tooth 43a, the clutch is completely disengaged. Therefore, when this state is established, the clutch housing 43 (spindle 12) is separated from the final gears 31 and 32 and can rotate freely. Also in this case, the friction ring 60 maintains the clutch OFF state by sliding and rotating with the outer circumference of the fixing ring 5 while receiving a frictional urging force.

As for the two clutches 41 and 42, when one final gear 31 (or 32) is rotating in the A direction, the other final gear 32 (or 31) is rotating in the B direction, so that one of them is always rotating. It turns on and the other turns off. That is, as long as the motor 15 (final gears 31 and 32) is rotating, this state is maintained. Further, when the motor 15 is stopped, it is necessary to keep the seatbelt 1 in a state where it can be pulled out. Therefore, it is a condition that a section in which both clutches 41 and 42 are turned off is secured. ..

Next, the overall operation of the seatbelt retractor 10 of the present embodiment will be described.
In the seatbelt retractor 10, as shown in FIG. 3, when the motor 15 is rotated forward (rotation N1), the first final gear 31 of the first gear mechanism 21 rotates in the A direction, and the second gear mechanism The second final gear 32 of 22 rotates in the B direction. In this case, the first clutch 41 is turned on and the second clutch 42 is turned off. Therefore, when the first clutch 41 is turned on, the first final gear 31 is connected to the spindle 12, the spindle 12 receives the power of the first gear mechanism 21 and rotates in the A direction at low speed and high torque, and the seat. The belt 1 is wound up with a high tension T1.

Next, as shown in FIG. 4, when the motor 15 is rotated in the reverse direction (rotation N2), the first final gear 31 of the first gear mechanism 21 rotates in the B direction, and the second final of the second gear mechanism 22 The gear 32 rotates in the A direction. In this case, the first clutch 41 is turned off and the second clutch 42 is turned on. Therefore, when the second clutch 42 is turned on, the second final gear 32 is connected to the spindle 12, the spindle 12 receives the power of the second gear mechanism 22 and rotates in the A direction at high speed and low torque, and the seat. The belt 1 is wound with a low tension T2.

In actual operation, when the possibility of a collision is detected by a monitoring sensor or the like (not shown), the motor 15 is rotated in the reverse direction (arrow N2) by an ECU (not shown) before the collision, as shown in FIG. The spindle 12 is rotated in the winding direction (A direction) with a low torque via the second final gear 32 of the mechanism 22, and the seat belt 1 is wound with a light tension T2. This function is pre-pretension (PP). When the possibility of collision disappears, the motor 15 is slightly rotated in the opposite direction (until the first clutch 41 is turned on) to return the seat belt 1 to a state in which it can be pulled out.

On the other hand, at the time of collision, as shown in FIG. 3, the motor 15 is rotated forward (arrow N1), and the spindle 12 is wound through the first final gear 31 of the first gear mechanism 21 to have a high torque in the winding direction (A direction). The seat belt 1 is wound up with a strong tension T1. As a result, the occupant binding force can be secured. This function is pretension (PT).

When the PT (pretensioner) is operating, if the seatbelt 1 receives an input in the pull-out direction equal to or greater than the set value while the first clutch 41 is ON, a broken portion (not shown) provided in the clutch housing 43 breaks. The motor 15 and the power transmission mechanism 20 are separated from the spindle 12. As a result, the motor 15 and the power transmission mechanism 20 can be prevented from affecting the characteristics of the load limiter or the energy absorption mechanism.

FIG. 9 is a characteristic diagram for explaining how the ON / OFF states of the two clutches are switched according to the rotation of the motor.
For example, if the gear ratio of the first gear mechanism 21 is 10 times the gear ratio of the second gear mechanism 22, and the motor needs to make one rotation in order to turn on / off the second clutch 42, the first clutch In order for 41 to turn ON / OFF, it is necessary for the motor to rotate 10 times.

As shown in FIG. 9, when the possibility of collision is detected, the motor is first rotated in the reverse direction (N2) to perform pre-pretension. In that case, when the motor is rotated in the reverse direction, the second clutch 42 is switched from OFF to ON while the motor makes one rotation. Then, the seat belt 1 is wound with a light tension (pre-pretension PP).

Next, when a collision is continuously detected, the motor switches from reverse rotation (N2) to forward rotation (N1). Then, while the motor makes one rotation, the second clutch 42 switches from ON to OFF, and at the same time, the first clutch 41 starts to switch from OFF to ON. At this time, since it takes time for the motor to rotate about 5 times before the first clutch 41 is turned on, there is a section in which both clutches 41 and 42 are turned off. The section in which both clutches are turned off in this way means a section in which the spindle 12 is free from both gear mechanisms 21 and 22. Therefore, by using the section, the seat belt 1 can be easily pulled out by the occupant, and the seat belt 1 can be wound by the take-up spring device 13.

As described above, according to the seatbelt retractor 10 of the present embodiment, both the pre-pretension function and the pre-tension function can be realized by switching the rotation direction of the motor 15. Therefore, the conventional explosive type pretensioner can be eliminated, and the configuration can be simplified. Therefore, it is possible to reduce the number of parts, thereby reducing the size and weight, and reducing the cost.

(Second Embodiment)
As shown in FIG. 10, the seatbelt retractor 110 of the second embodiment is different from the seatbelt retractor 10 of the first embodiment in the configuration of the first gear mechanism 121 and the second gear mechanism 122.

In the power transmission mechanism 120 of the seatbelt retractor 110 of the second embodiment, the first gear mechanism 121 meshes with the input gear 130 attached to the output shaft 15a of the motor 15 and the first intermediate gear 133. A second intermediate gear 134 that rotates coaxially with the first intermediate gear 133, a third intermediate gear 135 that meshes with the second intermediate gear 134, and a first final gear 131 that meshes with the third intermediate gear 135. Has been done. Further, the second gear mechanism 122 meshes with the input gear 130 attached to the output shaft 15a of the motor 15, the first intermediate gear 133 that meshes with the input gear 130, and the second final gear 132 that meshes with the first intermediate gear 133. And, it is composed of. Also in this case, condition 1 that the first final gear 131 and the second final gear 132 rotate in opposite directions when the motor 15 rotates, and condition 2 that the gear ratio of the first gear mechanism 121 is larger than the gear ratio of the second gear mechanism 122. It is configured to meet.
Other configurations are the same as those of the seatbelt retractor 10 of the first embodiment, so detailed description thereof will be omitted.

(Third Embodiment)
As shown in FIG. 11, the seatbelt retractor 210 of the third embodiment uses the output torque T1 of the first gear mechanism 221 as a pretensioner (PT) and pre-populates the output torque T2 of the second gear mechanism 22. -The point of use as a pretensioner (PP) is the same as that of the first embodiment, but the configuration of the power transmission mechanism is different from that of the first embodiment.
That is, in the seatbelt retractor 210, the gear ratio (reduction ratio) of the first gear mechanism 221 is set to be about 10 times larger than the gear ratio of the second gear mechanism 222 (condition 2). ). On the other hand, the seatbelt retractor 210 includes a control gear 231 and engages one of the first clutch 241 and the second clutch 242 via the control gear 231 according to the rotation direction of the electric actuator. Is disengaged, and the power of the electric actuator is selectively transmitted to the spindle 12 via either the first gear mechanism 221 or the second gear mechanism 222.
Hereinafter, the seatbelt retractor 210 of the third embodiment will be described focusing on the configuration of the power transmission mechanism 220.
In the present embodiment, the spindle 12 rotates in the B direction (clockwise when the retractor 10 is viewed from the left in FIG. 11) to wind up the seatbelt 1 and move in the A direction (counterclockwise). By rotating, the seat belt 1 is pulled out.

The seatbelt retractor 210 is a spindle 12 that winds up the seatbelt 1, a motor 15 as an electric actuator that generates power to rotate the spindle 12, and power transmission capable of transmitting power between the motor 15 and the spindle 12. It has a mechanism 220 and.

The power transmission mechanism 220 includes an input gear 230 attached to the output shaft 15a of the motor 15, a control gear 231 that meshes with the input gear 230, and a first gear mechanism 221 capable of transmitting the power of the motor 15 to the spindle 12. It has a second gear mechanism 222, and a first clutch 241 and a second clutch 242 that switch the power transmission of the first gear mechanism 221 and the second gear mechanism 222.

The first gear mechanism 221 is composed of a gear train of a first final gear 234 that meshes with the first first stage gear 232 and the first first stage gear 232 and can rotate integrally with the spindle 12. Further, the second gear mechanism 222 meshes with the second first stage gear 235, the intermediate gear 233 that meshes with the second first stage gear 235, and the gear of the second final gear 236 that meshes with the intermediate gear 233 and can rotate integrally with the spindle 12. Consists of columns.

The control gear 231 is arranged between the motor 15 and the first gear mechanism 221 and the second gear mechanism 222, and transmits the rotation of the motor 15 to the first gear mechanism 221 and the second gear mechanism 222.

Further, a first rotation angle sensor 251 capable of detecting the rotation angle of the control gear 231 is arranged in the vicinity of the control gear 231, and the first first stage is in the vicinity of the first first stage gear 232 of the first gear mechanism 221. A second rotation angle sensor 252 capable of detecting the rotation angle of the gear 232 is provided.

The first clutch 241 is arranged between the control gear 231 and the first first stage gear 232 of the first gear mechanism 221. The second clutch 242 is the second first stage gear 235 of the control gear 231 and the second gear mechanism 222. It is arranged between and. The first first stage gear 232 of the first gear mechanism 221, the control gear 231 and the second first stage gear 235 of the second gear mechanism 222 are arranged on the same support shaft 211.

As shown in FIGS. 12 and 13, the first clutch 241 and the second clutch 242 are arranged coaxially with the control gear 231 on both sides of the control gear 231. The first clutch 241 is interposed between the first gear mechanism 221 and the control gear 231 and engages with the first latch gear 243 in which a plurality of outer peripheral teeth 243a are formed on the outer periphery and the outer peripheral teeth 243a of the first latch gear 243. It includes a first coupling member 244 having a mating engaging claw 244a and a friction spring 248 that urges the first coupling member 244 in the engaging direction. The first clutch 241 turns on the connection between the first gear mechanism 221 and the control gear 231 when the motor 15 rotates in the forward direction, and turns on the connection between the first gear mechanism 221 and the control gear 231 when the motor 15 rotates in the opposite direction. The connection with 231 is turned off.

Further, the second clutch 242 is interposed between the second gear mechanism 222 and the control gear 231 and has a second latch gear 245 having a plurality of outer peripheral teeth 245a formed on the outer periphery thereof, and the outer peripheral teeth 245a of the second latch gear 245. It includes a second coupling member 246 having an engaging claw 246a that engages with the first coupling member 246, and a friction spring 248 that urges the first coupling member 244 in the engaging direction. The second clutch 242 turns on the connection between the second gear mechanism 222 and the control gear 231 when the motor 15 rotates in the opposite direction, and when the motor 15 rotates in the forward direction, the second gear mechanism 222 and the control gear The connection with 231 is turned off.

The first latch gear 243 of the first clutch 241 and the second latch gear 245 of the second clutch 242 are formed so that their outer peripheral teeth 243a and 245a are oriented in opposite directions in the circumferential direction. Further, the first latch gear 243 is formed so that the first first stage gear 232 is integrally rotated, and the second latch gear 245 is formed so that the second first stage gear 235 is integrally rotated.

The first coupling member 244 and the second coupling member 246 are arranged so as to sandwich the control gear 231 with the engaging claws 244a and 246a facing in opposite directions in the circumferential direction, and the base end portions 244b and 246b control each other. They are integrally connected by a connecting pin 247 that penetrates the side surface of the gear 231. Therefore, the first coupling member 244 and the second coupling member 246 swing in opposite directions with respect to the connecting pin 247, and rotate in the same direction together with the control gear 231 as the control gear 231 rotates.

Further, in the friction spring 248, one end 248a is in contact with the engaging claws 244a and 246a, and the other end 248b is wound around the support shaft 211. When the support shaft 211 rotates, the friction spring 248 uses frictional resistance between the support shaft 211 and the other end 248b of the friction spring 248 to cause the engaging claws 244a to be moved to the outer peripheral teeth of the first latch gear 243 according to the rotation direction of the support shaft 211. The engagement claw 246a is urged in the direction of engaging with the 243a or in the direction of engaging with the outer peripheral teeth 245a of the second latch gear 245.

As a result, when the control gear 231 is rotated in the A direction by the forward rotation of the motor 15 (arrow N1), the first coupling member 244 and the first latch gear 243 are engaged (the first clutch 241 is ON), and the second coupling is performed. The engagement between the member 246 and the second latch gear 245 is released (the second clutch 242 is OFF). Further, when the control gear 231 rotates in the B direction due to the reverse rotation of the motor 15 (arrow N2), the engagement between the first coupling member 244 and the first latch gear 243 is released (the first clutch 241 is OFF), and the first clutch 241 is released. The two coupling members 246 and the second latch gear 245 are engaged (the second clutch 242 is ON). That is, the first clutch 241 and the second clutch 242 are switched on and off by the rotation of the control gear 231 and the connection is not turned on at the same time.

Next, the operation of the power transmission mechanism 220 will be described with reference to FIGS. 14 and 15.
As shown in FIGS. 14A and 15A, when the motor 15 is stopped, the first coupling member 244 and the second coupling member 246 are subjected to the action of the friction spring 248 to cause the first coupling member 244. The engagement between the engaging claw 244a and the outer peripheral tooth 243a of the first latch gear 243 is released (the first clutch is turned off), and the engaging claw 246a of the second coupling member 246 and the outer peripheral tooth 245a of the second latch gear 245 Is in the position where the engagement is disengaged (second clutch OFF). That is, both the first clutch 241 and the second clutch 242 are in the OFF state. Therefore, each gear of the first gear mechanism 221 and the second gear mechanism 222 can rotate freely, and the spindle 12 can freely rotate by pulling out and winding the seat belt 1. The arrow L in FIG. 14A shows the power transmission path at this time.

Here, when the motor 15 rotates in the forward direction (arrow N1), the control gear 231 together with the first coupling member 244 and the second coupling member 246, as shown in FIGS. 14 (b) and 15 (a) to (c). Rotating in the A direction, the engaging claw 244a of the first coupling member 244 and the outer peripheral teeth 243a of the first latch gear 243 are engaged with each other, and the first clutch 241 is turned on. As a result, the first first stage gear 232 integrally molded with the first latch gear 243 rotates in the A direction. On the other hand, in the second clutch 242, the engaging claw 246a of the second coupling member 246 is separated from the outer peripheral teeth 245a of the second latch gear 245, and the engagement is completely released (second clutch OFF).

The rotation of the first first stage gear 232 in the A direction is transmitted to the first final gear 234, and the first final gear 234 rotates in the B direction. As a result, the spindle 12 receives the power of the first gear mechanism 221 and rotates in the B direction at a low speed and with a high torque, and winds up the seat belt 1 with a high tension T1 (pretension PT). At that time, since the second clutch 242 is in the OFF state, the second final gear 236, the intermediate gear 233, and the second first stage gear 235 rotate freely. The arrow M in FIG. 14B shows the power transmission path at this time.

When the motor 15 is rotated in the reverse direction (arrow N2), both the first clutch 241 and the second clutch 242 are in the OFF state (FIG. 15 (a)) in the reverse order (FIGS. 15 (c) to (a)). )) Return.

Further, when the motor 15 rotates in the reverse direction (arrow N2), as shown in FIGS. 14 (b) and 15 (d) to (f), the control gear 231 B together with the first coupling member 244 and the second coupling member 246. Rotating in the direction, the engaging claw 246a of the second coupling member 246 engages with the outer peripheral teeth 245a of the second latch gear 245, the second clutch 242 is turned on, and the second first stage integrally molded with the second latch gear 245. The gear 235 rotates in the B direction (FIG. 15 (f)). On the other hand, in the first clutch 241 the engaging claw 244a of the first coupling member 244 is separated from the outer peripheral teeth 243a of the first latch gear 243 and the engagement is completely released (first clutch OFF).

The rotation of the second first stage gear 235 in the B direction is transmitted to the second final gear 236 via the intermediate gear 233, and the second final gear 236 rotates in the B direction. As a result, the spindle 12 receives the power of the second gear mechanism 222 and rotates in the B direction at high speed and with low torque, and winds up the seat belt 1 with a light tension T2 (pre-pretension PP). At that time, since the first clutch 241 is in the OFF state, the first final gear 234 and the first first stage gear 232 can rotate freely. The arrow N in FIG. 14B shows the power transmission path at this time.

Subsequently, when the motor 15 is rotated forward (arrow N1), both the first clutch 241 and the second clutch 242 are in the OFF state (FIG. 15 (d)) in the reverse order (FIGS. 15 (f) to (d)). )) Return.

Further, in order to allow the seatbelt 1 to be freely pulled out and wound up, the first clutch 241 and the second clutch 242 are both in a non-engaged (OFF) state except when the spindle 12 is driven by the motor 15. Need to hold. The disengagement of the first clutch 241 and the second clutch 242 is performed by rotating the motor 15 in the direction of disengaging the first clutch 241 or the second clutch 242 in the engaged state. However, if the motor 15 rotates too much beyond the neutral point (both the first and second clutches 241 and 242 are in the OFF state), the other clutch that was in the disengaged state is turned on, which is appropriate. It is necessary to stop the motor 15 at the rotation position.

For example, when disengaging the first clutch 241, the first rotation angle sensor 251 detects the rotation angle of the control gear 231 and the second rotation angle sensor 252 detects the rotation angle of the first first stage gear 232. Then, as shown in FIG. 16, the relative rotation angle between the rotation angle of the control gear 231 detected by the first rotation angle sensor 251 and the rotation angle of the first first stage gear 232 detected by the second rotation angle sensor 252 is determined. When the predetermined clutch release angle θoff is reached, the rotation of the motor 15 is stopped. As a result, both the first and second clutches 241,242 are held in the OFF state.

Similarly, when disengaging the second clutch 242, when the relative rotation angle between the rotation angle of the control gear 231 and the rotation angle of the second first stage gear 235 reaches a predetermined clutch disengagement angle θoff, the motor 15 Stop the rotation of. However, since the second first stage gear 235 does not have a rotation angle sensor, the second first stage gear is based on the following equation from the rotation angle of the first first stage gear 232 detected by the second rotation angle sensor 252 provided on the first first stage gear 232. The rotation angle of 235 is calculated and the rotation of the motor 15 is stopped.
Rotation angle of the second first stage gear 235 = Gb / Ga × detection value of the second rotation angle sensor 252 Here, Gb is the gear ratio of the second gear mechanism 222, and Ga is the gear ratio of the first gear mechanism 221.
In this way, by providing the second rotation angle sensor 252 on the side of the first gear mechanism 221 having a high gear ratio, it is possible to detect the angle with high accuracy.

Therefore, also in the seatbelt retractor 210 of the present embodiment, both the pre-pretension function and the pre-tension function can be realized by switching the rotation direction of the motor 15. Therefore, the conventional explosive type pretensioner can be eliminated, and the configuration can be simplified. Therefore, it is possible to reduce the number of parts, thereby reducing the size and weight, and reducing the cost.

(Fourth Embodiment)
As shown in FIG. 17, in the seat belt retractor 310 of the fourth embodiment, the power transmission mechanism 320 includes a control gear 331, and the first clutch 341 via the control gear 331 according to the rotation direction of the electric actuator. And one of the second clutch 342 are engaged and one of the other is disengaged, and the power of the electric actuator is selectively transferred to the spindle 12 via either the first gear mechanism 321 or the second gear mechanism 322. It is similar to the third embodiment in that it is transmitted, but is different from the third embodiment in a specific configuration.

The seatbelt retractor 310 is a spindle 12 that winds up the seatbelt 1, a motor 15 as an electric actuator that generates power to rotate the spindle 12, and power transmission capable of transmitting power between the motor 15 and the spindle 12. It has a mechanism 320 and.

The power transmission mechanism 320 includes an input gear 330 attached to the output shaft 15a of the motor 15, a control gear 331 that meshes with the input gear 330, a first gear mechanism 321 and a second gear mechanism 322, and a first clutch. It has 341 and a second clutch 342.

The first gear mechanism 321 is composed of a gear train of a first first stage gear 333 and a first final gear 335 that meshes with the first first stage gear 333. Further, the second gear mechanism 322 is composed of a second first stage gear 336, an intermediate gear 334 that meshes with the second first stage gear 336, and a gear train of a second final gear 337 that meshes with the intermediate gear 334.

As shown in FIGS. 19A, 19C, and 19E, the first clutch 341 includes a first clutch housing 343 that rotates integrally with the first first stage gear 333 of the first gear mechanism 321 and a first clutch housing 343. A first poul 346 that can be coupled to the inner peripheral teeth 343a of the clutch housing 343 is provided. The first poul 346 is slidably inserted into the powl sliding groove 331a formed in the control gear 331, and rotates integrally with the control gear 331.

Further, as shown in FIGS. 19B, 19D, and 19F, the second clutch 342 includes a second clutch housing 347 that rotates integrally with the second first stage gear 336 of the second gear mechanism 322. A second poul 348 that can be coupled to the inner peripheral teeth 347a of the second clutch housing 347 is provided. The second poul 348 is slidably inserted into the powl sliding groove 331a formed in the control gear 331, and rotates integrally with the control gear 331.
19 (b), (d), and (f) are schematic front views of the second clutch 342 viewed from the left at the axial intermediate position of the control gear 331.

As shown in FIG. 18B, the first poul 346 and the second poul 348 have an engaging claw 346a that can be coupled to the inner peripheral tooth 343a of the first clutch housing 343 and an inner peripheral tooth of the second clutch housing 347. The engaging claws 348a that can be coupled to the 347a are directed in opposite directions, and the respective base end portions are integrally connected by the connecting portion 350.

The control gear 331, the first first stage gear 333, and the second first stage gear 336 are provided on the same shaft 311. A friction ring 349 that is in frictional contact with the shaft 311 is fitted to the shaft 311. With reference to FIG. 19A, the protrusion 349a of the friction ring 349 is engaged with the engagement groove 346b of the first Paul 346. The configuration and operation of the first poul 346, the second poul 348, and the friction ring 349 of the present embodiment are the first embodiment shown in FIG. 5, except that the first poul 346 and the second poul 348 operate integrally. Since it is the same as the configuration of the form, detailed description thereof will be omitted.

Next, the operation of the power transmission mechanism 320 will be described with reference to FIGS. 17 and 19.
As shown in FIGS. 19A and 19B, when the motor 15 is stopped and both the first clutch 341 and the second clutch 342 are in the OFF state, the first gear mechanism 321 and the second gear mechanism 322 Each gear can rotate freely, and the seat belt 1 can be pulled out and wound by the rotation of the spindle 12.

Here, when the motor 15 rotates in the forward direction (arrow N1), the control gear 331 rotates in the A direction together with the first poul 346 and the second poul 348 as shown in FIGS. 19 (c) and 19 (d). At this time, due to the action of the friction ring 349, the first poul 346 moves in the powl sliding groove 331a, and the engaging claw 346a is coupled to the inner peripheral teeth 343a of the first clutch housing 343 (the first clutch 341 is turned on). ), The first clutch housing 343 rotates in the A direction together with the first first stage gear 333. At the same time, the engaging claw 348a of the second pole 348 is completely separated from the inner peripheral teeth 347a of the second clutch housing 347 (the second clutch 342 is OFF). The rotation of the first first stage gear 333 in the A direction is transmitted to the first final gear 335, and the first final gear 335 rotates in the B direction. As a result, the spindle 12 receives the power of the first gear mechanism 321 and rotates in the B direction at a low speed and with a high torque, and winds up the seat belt 1 with a high tension T1 (pretension PT).

Further, when the first clutch 341 and the second clutch 342 are both in the OFF state (see FIGS. 19 (a) and 19 (b)) and the motor 15 rotates in the reverse direction (arrow N2), FIGS. 19 (e) and 19 (f). ), The control gear 331 rotates in the B direction together with the first poul 346 and the second poul 348, and the first and second powls 346 and 348 are moved in the powl sliding groove 331a by the action of the friction ring 349. , The engaging claw 346a of the first pole 346 moves in the opposite direction to the above, and is completely separated from the inner peripheral teeth 343a of the first clutch housing 343 (FIG. 19 (e)), and the engagement of the second pole 348 is performed. The claw 348a is coupled to the inner peripheral teeth 347a of the second clutch housing 347, and the second clutch housing 347 rotates in the B direction together with the second first stage gear 336 (FIG. 19 (f)).

The rotation of the second first stage gear 336 in the B direction is transmitted to the second final gear 337 via the intermediate gear 334, and the second final gear 337 rotates in the B direction. As a result, the spindle 12 receives the power of the second gear mechanism 322 and rotates in the B direction at high speed and with low torque, and winds up the seat belt 1 with a light tension T2 (pre-pretension PP).

Therefore, also in the seatbelt retractor 310 of the present embodiment, both the pre-pretension function and the pre-tension function can be realized by switching the rotation direction of the motor 15. Therefore, the conventional explosive type pretensioner can be eliminated, and the configuration can be simplified. Therefore, it is possible to reduce the number of parts, thereby reducing the size and weight, and reducing the cost.

The present invention is not limited to the above-described embodiment, and can be appropriately modified, improved, and the like.
For example, in the above embodiment, the case where the drive mechanism is applied to the retractor for the seat belt has been described, but the drive mechanism of the present invention can be widely used for other drive systems that require two variable output torques. is there.

Further, in the first embodiment, the idle gear 33 is provided between the output shaft 15a of the motor 15 and the second final gear 32 in the second gear mechanism 22, but is not limited thereto. That is, in the present invention, either one of the first gear mechanism or the second gear mechanism reverses the rotation direction of the output shaft of the electric actuator between the electric actuator and the first final gear or the second final gear. Any configuration may be provided as long as it is provided with an idle gear.

Further, in the third embodiment, the first rotation angle sensor 251 is arranged in the vicinity of the control gear 231 and the second rotation angle sensor 252 is arranged in the vicinity of the first first stage gear 232. The rotation angle sensor 251 may be located near the output shaft 15a of the motor 15 or the input gear 230, and the second rotation angle sensor 252 is arranged near the first final gear 234 of the first gear mechanism 221 having a high gear ratio. May be good. As the first and second rotation angle sensors 251,252, a magnetic angle sensor or an optical angle sensor can be used.

The power transmission mechanism of the present invention includes "a first gear mechanism capable of transmitting power from the electric actuator to the operating shaft (spindle) and power from the electric actuator to the operating shaft (spindle). When the electric actuator rotates in the forward direction, the first gear mechanism is coupled to the second gear mechanism capable of transmitting power to the actuating shaft (spindle) so as to transmit power from the actuator to the electric actuator. When the actuator rotates in the opposite direction, the first clutch that releases the power transmission of the first gear mechanism and when the electric actuator rotates in the opposite direction, the second gear mechanism moves from the actuator to the operating shaft (the said). It may be configured to have a second clutch that is coupled so as to transmit power to the spindle) and releases the power transmission of the second gear mechanism when the electric actuator rotates in the forward direction.
That is, in the first embodiment, the condition 1 “the first final gear 31 of the first gear mechanism 21 and the second final gear 32 of the second gear mechanism 22 rotate in opposite directions when the motor 15 rotates. The gear train of the first gear mechanism 21 and the gear train of the second gear mechanism 22 are configured ”, but as is clear from the third and fourth embodiments, the present invention is limited to this. It is not something that is done.

1 Seatbelts 10, 110, 210, 310 Seatbelt retractors 12 Spindles 15 Motors (electric actuators)
20,120,220,320 Power transmission mechanism 21,121,221,321 First gear mechanism 22,122,222,322 Second gear mechanism 30,130,230,330 Input gear 31,131,234,335 First Final gear 32,132,236,337 2nd final gear 33 Idle gear 41,241,341 1st clutch 42,242,342 2nd clutch 43 Clutch housing 43a Internal teeth 50 Paul 133,233,334 Intermediate gear (idle gear) )
211 Support shaft 231 and 331 Control gear 232, 333 First first stage gear 235, 336 Second first stage gear 243 First latch gear 243a, 245a Outer teeth 244 First coupling member 245 Second latch gear 246 Second coupling member 251 First rotation angle Sensor 252 Second rotation angle sensor 343 First clutch housing 343a, 347a Inner peripheral tooth 346 First Paul (first coupling member)
347 2nd Clutch Housing 348 2nd Paul (2nd Coupling Member)
N1 Forward rotation N2 Reverse rotation θoff Clutch release angle Ga Gear ratio of the first gear mechanism Gb Gear ratio of the second gear mechanism

Claims (16)

When one direction of the rotation direction is the A direction and the other direction is the B direction, the operating shaft that can rotate in the A direction and the B direction,
An electric actuator that generates rotational output in the forward and reverse directions to rotate the operating shaft, and
A power transmission mechanism that transmits power between the electric actuator and the operating shaft,
With
The power transmission mechanism
A first gear mechanism that has a first final gear that can rotate integrally with the operating shaft and can transmit power from the electric actuator.
A second gear mechanism that has a second final gear that can rotate integrally with the operating shaft and can transmit power from the electric actuator.
A control gear arranged between the electric actuator and the first gear mechanism and the second gear mechanism to transmit the rotation of the electric actuator to the first gear mechanism and the second gear mechanism.
Intervened between the first gear mechanism and the control gear, when the electric actuator rotates in the forward direction, the connection between the first gear mechanism and the control gear is turned on, and the electric actuator moves in the opposite direction. When rotating, the first clutch that turns off the connection between the first gear mechanism and the control gear, and
Intervened between the second gear mechanism and the control gear, when the electric actuator rotates in the opposite direction, the connection between the second gear mechanism and the control gear is turned on, and the electric actuator moves in the forward direction. It has a second clutch that turns off the connection between the second gear mechanism and the control gear when rotating.
The gear ratio of the first gear mechanism and the gear ratio of the second gear mechanism are set to different values .
The first clutch can be coupled to a first latch gear that rotates integrally with the first first stage gear of the first gear mechanism and outer peripheral teeth of the first latch gear, and can rotate integrally with the control gear. With one coupling member,
The second clutch can be coupled to a second latch gear that rotates integrally with the second first stage gear of the second gear mechanism and outer peripheral teeth of the second latch gear, and can rotate integrally with the control gear. With 2 coupling members
The first first stage gear and the second first stage gear are provided coaxially with the control gear.
Said first coupling member and the second coupling member and you characterized by being connected to each other drive kinematic mechanism. When one direction of the rotation direction is the A direction and the other direction is the B direction, the operating shaft that can rotate in the A direction and the B direction,
An electric actuator that generates rotational output in the forward and reverse directions to rotate the operating shaft, and
A power transmission mechanism that transmits power between the electric actuator and the operating shaft,
With
The power transmission mechanism
A first gear mechanism that has a first final gear that can rotate integrally with the operating shaft and can transmit power from the electric actuator.
A second gear mechanism that has a second final gear that can rotate integrally with the operating shaft and can transmit power from the electric actuator.
A control gear arranged between the electric actuator and the first gear mechanism and the second gear mechanism to transmit the rotation of the electric actuator to the first gear mechanism and the second gear mechanism.
Intervened between the first gear mechanism and the control gear, when the electric actuator rotates in the forward direction, the connection between the first gear mechanism and the control gear is turned on, and the electric actuator moves in the opposite direction. When rotating, the first clutch that turns off the connection between the first gear mechanism and the control gear, and
Intervened between the second gear mechanism and the control gear, when the electric actuator rotates in the opposite direction, the connection between the second gear mechanism and the control gear is turned on, and the electric actuator moves in the forward direction. It has a second clutch that turns off the connection between the second gear mechanism and the control gear when rotating.
The gear ratio of the first gear mechanism and the gear ratio of the second gear mechanism are set to different values.
The first clutch can be coupled to the first clutch housing that rotates integrally with the first first stage gear of the first gear mechanism and the inner peripheral teeth of the first clutch housing, and rotates integrally with the control gear. With a possible first coupling member,
The second clutch can be coupled to the second clutch housing that rotates integrally with the second first stage gear of the second gear mechanism and the inner peripheral teeth of the second clutch housing, and rotates integrally with the control gear. With a possible second coupling member,
The first first stage gear and the second first stage gear are provided coaxially with the control gear.
Said first coupling member and the second coupling member and you characterized by being connected to each other drive kinematic mechanism. Either one of the first gear mechanism or the second gear mechanism reverses the rotation direction of the output shaft of the electric actuator between the electric actuator and the first final gear or the second final gear. The drive mechanism according to claim 1 or 2 , further comprising an idle gear. The first clutch and the second clutch are clutches having the same characteristics, and when the electric actuator is OFF, both the first clutch and the second clutch are OFF for the connection between the gear mechanism and the control gear. The drive mechanism according to any one of claims 1 to 3 , wherein the drive mechanism can be held in the state of the clutch. A first rotation angle sensor disposed between the first and second clutches and the electric actuator to detect a rotation angle, and
A second rotation angle sensor, which is arranged between the first clutch and the operating shaft or between the second clutch and the operating shaft and detects a rotation angle, is provided.
When the relative angle difference between the first rotation angle sensor and the second rotation angle sensor reaches a predetermined value, the disengagement rotation of the first clutch and the second clutch by the electric actuator is stopped. The drive mechanism according to any one of claims 1 to 4. When one direction of the rotation direction is the A direction and the other direction is the B direction, the operating shaft that can rotate in the A direction and the B direction,
An electric actuator that generates rotational output in the forward and reverse directions to rotate the operating shaft, and
A power transmission mechanism that transmits power between the electric actuator and the operating shaft,
With
The power transmission mechanism
A first gear mechanism that has a first final gear that can rotate integrally with the operating shaft and can transmit power from the electric actuator.
A second gear mechanism that has a second final gear that can rotate integrally with the operating shaft and can transmit power from the electric actuator.
A control gear arranged between the electric actuator and the first gear mechanism and the second gear mechanism to transmit the rotation of the electric actuator to the first gear mechanism and the second gear mechanism.
Intervened between the first gear mechanism and the control gear, when the electric actuator rotates in the forward direction, the connection between the first gear mechanism and the control gear is turned on, and the electric actuator moves in the opposite direction. When rotating, the first clutch that turns off the connection between the first gear mechanism and the control gear, and
Intervened between the second gear mechanism and the control gear, when the electric actuator rotates in the opposite direction, the connection between the second gear mechanism and the control gear is turned on, and the electric actuator moves in the forward direction. It has a second clutch that turns off the connection between the second gear mechanism and the control gear when rotating.
The gear ratio of the first gear mechanism and the gear ratio of the second gear mechanism are set to different values.
A first rotation angle sensor disposed between the first and second clutches and the electric actuator to detect a rotation angle, and
A second rotation angle sensor, which is arranged between the first clutch and the operating shaft or between the second clutch and the operating shaft and detects a rotation angle, is provided.
When the relative angle difference between the first rotation angle sensor and the second rotation angle sensor reaches a predetermined value, the disengagement rotation of the first clutch and the second clutch by the electric actuator is stopped. Drive mechanism. The drive mechanism according to claim 5 or 6, wherein the second rotation angle sensor is arranged in the gear mechanism on the side having a larger gear ratio among the first gear mechanism and the second gear mechanism. .. The rotation angle of the first gear mechanism or the second gear mechanism not provided with the second rotation angle sensor is the detection angle of the second rotation angle sensor, the gear ratio of the first gear mechanism, and the second gear mechanism. The drive mechanism according to claim 7, wherein the drive mechanism is obtained by calculation from the ratio to the gear ratio of the above. When the winding direction of the seat belt is the A direction and the pulling direction of the seat belt is the B direction, the spindle that can rotate in the A direction and the B direction,
An electric actuator that generates rotational output in the forward and reverse directions to rotate the spindle, and
A power transmission mechanism that transmits power between the electric actuator and the spindle,
With
The power transmission mechanism
A first gear mechanism that has a first final gear that can rotate integrally with the spindle and can transmit power from the electric actuator.
A second gear mechanism that has a second final gear that can rotate integrally with the spindle and can transmit power from the electric actuator.
A control gear arranged between the electric actuator and the first gear mechanism and the second gear mechanism to transmit the rotation of the electric actuator to the first gear mechanism and the second gear mechanism.
Intervened between the first gear mechanism and the control gear, when the electric actuator rotates in the forward direction, the connection between the first gear mechanism and the control gear is turned on, and the electric actuator moves in the opposite direction. When rotating, the first clutch that turns off the connection between the first gear mechanism and the control gear, and
Intervened between the second gear mechanism and the control gear, when the electric actuator rotates in the opposite direction, the connection between the second gear mechanism and the control gear is turned on, and the electric actuator moves in the forward direction. It has a second clutch that turns off the connection between the second gear mechanism and the control gear when rotating.
The gear ratio of the first gear mechanism and the gear ratio of the second gear mechanism are set to different values .
The first clutch can be coupled to a first latch gear that rotates integrally with the first first stage gear of the first gear mechanism and outer peripheral teeth of the first latch gear, and can rotate integrally with the control gear. With one coupling member,
The second clutch can be coupled to a second latch gear that rotates integrally with the second first stage gear of the second gear mechanism and outer peripheral teeth of the second latch gear, and can rotate integrally with the control gear. With 2 coupling members
The first first stage gear and the second first stage gear are provided coaxially with the control gear.
Retractor for sheet Toberuto, characterized by being connected to each other and the second coupling member and the first coupling member. When the winding direction of the seat belt is the A direction and the pulling direction of the seat belt is the B direction, the spindle that can rotate in the A direction and the B direction,
An electric actuator that generates rotational output in the forward and reverse directions to rotate the spindle, and
A power transmission mechanism that transmits power between the electric actuator and the spindle,
With
The power transmission mechanism
A first gear mechanism that has a first final gear that can rotate integrally with the spindle and can transmit power from the electric actuator.
A second gear mechanism that has a second final gear that can rotate integrally with the spindle and can transmit power from the electric actuator.
A control gear arranged between the electric actuator and the first gear mechanism and the second gear mechanism to transmit the rotation of the electric actuator to the first gear mechanism and the second gear mechanism.
Intervened between the first gear mechanism and the control gear, when the electric actuator rotates in the forward direction, the connection between the first gear mechanism and the control gear is turned on, and the electric actuator moves in the opposite direction. When rotating, the first clutch that turns off the connection between the first gear mechanism and the control gear, and
Intervened between the second gear mechanism and the control gear, when the electric actuator rotates in the opposite direction, the connection between the second gear mechanism and the control gear is turned on, and the electric actuator moves in the forward direction. It has a second clutch that turns off the connection between the second gear mechanism and the control gear when rotating.
The gear ratio of the first gear mechanism and the gear ratio of the second gear mechanism are set to different values.
The first clutch can be coupled to the first clutch housing that rotates integrally with the first first stage gear of the first gear mechanism and the inner peripheral teeth of the first clutch housing, and rotates integrally with the control gear. With a possible first coupling member,
The second clutch can be coupled to the second clutch housing that rotates integrally with the second first stage gear of the second gear mechanism and the inner peripheral teeth of the second clutch housing, and rotates integrally with the control gear. With a possible second coupling member,
The first first stage gear and the second first stage gear are provided coaxially with the control gear.
Features and to Resid Toberuto retractor that are connected to each other and the second coupling member and the first coupling member. Either one of the first gear mechanism or the second gear mechanism reverses the rotation direction of the output shaft of the electric actuator between the electric actuator and the first final gear or the second final gear. The seatbelt retractor according to claim 9 or 10 , further comprising an idle gear. The first clutch and the second clutch are clutches having the same characteristics, and when the electric actuator is OFF, both the first clutch and the second clutch turn off the connection between the final gear and the spindle. The retractor for a seat belt according to any one of claims 9 to 11 , wherein the retractor can be held in a clutched state. A first rotation angle sensor disposed between the first and second clutches and the electric actuator to detect a rotation angle, and
A second rotation angle sensor, which is arranged between the first clutch and the spindle or between the second clutch and the spindle to detect a rotation angle, is provided.
When the relative angle difference between the first rotation angle sensor and the second rotation angle sensor reaches a predetermined value, the disengagement rotation of the first clutch and the second clutch by the electric actuator is stopped. The seatbelt retractor according to any one of claims 9 to 12. When the winding direction of the seat belt is the A direction and the pulling direction of the seat belt is the B direction, the spindle that can rotate in the A direction and the B direction,
An electric actuator that generates rotational output in the forward and reverse directions to rotate the spindle, and
A power transmission mechanism that transmits power between the electric actuator and the spindle,
With
The power transmission mechanism
A first gear mechanism that has a first final gear that can rotate integrally with the spindle and can transmit power from the electric actuator.
A second gear mechanism that has a second final gear that can rotate integrally with the spindle and can transmit power from the electric actuator.
A control gear arranged between the electric actuator and the first gear mechanism and the second gear mechanism to transmit the rotation of the electric actuator to the first gear mechanism and the second gear mechanism.
Intervened between the first gear mechanism and the control gear, when the electric actuator rotates in the forward direction, the connection between the first gear mechanism and the control gear is turned on, and the electric actuator moves in the opposite direction. When rotating, the first clutch that turns off the connection between the first gear mechanism and the control gear, and
Intervened between the second gear mechanism and the control gear, when the electric actuator rotates in the opposite direction, the connection between the second gear mechanism and the control gear is turned on, and the electric actuator moves in the forward direction. It has a second clutch that turns off the connection between the second gear mechanism and the control gear when rotating.
The gear ratio of the first gear mechanism and the gear ratio of the second gear mechanism are set to different values.
A first rotation angle sensor disposed between the first and second clutches and the electric actuator to detect a rotation angle, and
A second rotation angle sensor, which is arranged between the first clutch and the spindle or between the second clutch and the spindle to detect a rotation angle, is provided.
When the relative angle difference between the first rotation angle sensor and the second rotation angle sensor reaches a predetermined value, the disengagement rotation of the first clutch and the second clutch by the electric actuator is stopped. Retractor for seat belts. The seatbelt according to claim 13 or 14, wherein the second rotation angle sensor is arranged in the gear mechanism on the side having a larger gear ratio among the first gear mechanism and the second gear mechanism. For retractor. The rotation angle of the first gear mechanism or the second gear mechanism not provided with the second rotation angle sensor is the detection angle of the second rotation angle sensor, the gear ratio of the first gear mechanism, and the second gear mechanism. The retractor for a seat belt according to claim 15, wherein the retractor for a seat belt is obtained by calculation from the ratio to the gear ratio of the above.

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